The present invention relates to apparatus and methods for the accurate measurement of the mass of a fluid. In particular this invention pertains to accurate real time mass measurement of fluids at remote locations.
The invention is particularly directed to the real time measurement of the mass of urine discharged by astronauts. It is also useful in the separation and determination of the mass of a liquid mixed with a gas immediately at the time of separation.
In the past few years man has made great strides in exploring outer space. The NASA space program has been characterized by continuous and sometimes spectacular advances. Of course, in making advances in such a program, many problems have been encountered.
One such problem in space travel is the ability to accurately measure and keep bio-medical data on each astronaut to make sure he is in good health. It has been observed that the mass of urine discharged during each micturition of an astronaut is significant as a good diagnostic indicator of whether an astronaut is having some biological malfunction. Thus, it has been found to be important to have an accurate measure of the mass of urinary discharges each time an astronaut urinates.
Another such problem is how to make astronauts as comfortable as possible on long space trips. One way to keep astronauts comfortable is to make the normal body functions of eating and excreting as earth-like as possible. The currently used roll-on cuff for urination in space leaves much to be desired in making the astronaut feel comfortable and earth-like in his environment.
The problem of accurate measurement is further compounded by the necessity of providing a way to accurately measure the urine mass of an astronaut in his zero gravity environment. Most scales, as we known them today, are gravity dependent. The lack of gravity in space creates additional problems in that fluid to be collected will not collect and stay in a container while the measurement of its mass is being made.
Prior methods used in the determination of the mass of urine have been post-flight gravimetric determination based on the mass of the fluid being collected, during flight, but this post-flight bio-medical data does not provide the inflight data which is needed to keep real time medical checks on the astronauts.
Another problem associated with post-flight urine analysis is the filling of the containers without the astronauts having to handle the container. In addition, the astronaut has had to wear a roll-on cuff in order to feed urine into a post-flight collection system. In order to solve these problems it is important to find a means whereby the astronaut can automatically fill the device to be used in measuring the mass of the urine and also to provide the astronaut with a means of collecting wherein the discharge of urine can be more earth-like. Further, as the space hardware designers have begun to develop pneumatic collection systems for urine and fluids, it has become important that the device developed for the measurement of the mass of the urine also be compatible with a pneumatic collection, and yet not sacrifice the accuracy of the measurement of the mass of an astronaut's urine.